Hello everyone,

I've benefited much from this forum trying to keep my 06 LR3 V6 4.0 running that I wanted to share a recent finding. For years I have had this issue where the LR3 will intermittently just crank when trying to start the engine but never actually start (i.e. it is not firing). When this happens is completely random and I have never been truly stranded because of it as I always somehow get it started after a lot of cranking. On the forums there are a bunch of people talking about similar symptoms (but don't confuse this with the "starter won't engage or turn over the engine" issue). It seems that more than one person has literally traded their otherwise loved LR3 because they couldn't resolve the issue. Please note (and I don't know why) my LR3 at least never reported that any error has ever occurred - i.e. there were no trouble codes ever thrown when all this cranking but no starting occurred. Here is what I did:

1) First I replaced the crankshaft position sensor - on the V6 it is on the bell housing of the transmission. This fixed the issue for awhile then it returned.
2) I replaced the camshaft position sensor - this also fixed the issue but it eventually returned.
3) Running out of ideas I started trying the "unplug the #1 cylinder spark plug trick" - this seemed to work sometimes but was not a sure thing. I checked grounding by running temporary straps between points on the engine and the body (nothing). I was getting desperate - luckily the LR3 was in the garage and not starting so I had some time to really look it over. Finally..
4) I noticed that the way the camshaft position sensor wiring/connector has to make a 180 degree bend from the wiring loom to the sensor itself. This seemed like a poor design and, sure enough, removing some wire shielding - I found a somewhat "pinched" bend in the wiring. I gently wiggled this wiring and - boom - the LR3 started like normal. I unplugged the sensor and tried starting - crank but no start. I plugged it back in - started right back up. I did this a number of times and it always worked and no codes were ever thrown.

So, I eventually replaced the wiring connector for the camshaft position sensor. That was a couple of years ago and I have never had this problem again. I think what was happening is that this intermittent connectivity to the camshaft position sensor was simply fixed by my many attempts to replace other parts, unhook spark plugs, etc. Because it is fairly exposed, just brushing up against it while working in the engine bay was probably equivalent to "giggling the connector." So, that is my experience with a difficult to figure out issue. It seems the V8's have a similar problem but I don't know how likely it is that the wiring connector on the V8s is also poorly designed. If you are having this sort of issue (particularly with no codes) consider checking this connector and wiring very closely. I hope this is helpful.

WyoExile

 

Hi and thanks for your write-up. This sounds fairly similar to my problem however I have not gone after the cam sensors yet. I also have the 4.4 v8 so there will be a lot of differences. You comment however that you have heard the v8's have a similar problem? Do you know anything more about that? I will go over the wiring more closely tonight but if you have anything more I'd be interested to hear it. I have posted by troubleshooting up to this point in another part of the forum.

 

I know it's been a while but Thank you! I've replaced the battery several times, alternator, crankshaft position sensor and was thinking of dropping the starter next. I've looked at the wiring but did not check behind the harness... Will do so now.

Same issue .. Intermittent crank no start with no CEL